U.S. patent application number 12/442294 was filed with the patent office on 2010-03-18 for devices and methods for ligating anatomical structures.
This patent application is currently assigned to Mayo Foundation for Medical Education and Research. Invention is credited to Samuel J. Asirvatham, Charles J. Bruce, Paul A. Friedman.
Application Number | 20100069925 12/442294 |
Document ID | / |
Family ID | 39156684 |
Filed Date | 2010-03-18 |
United States Patent
Application |
20100069925 |
Kind Code |
A1 |
Friedman; Paul A. ; et
al. |
March 18, 2010 |
DEVICES AND METHODS FOR LIGATING ANATOMICAL STRUCTURES
Abstract
Devices and methods for ligating anatomical structures are
provided herein. In particular, the devices and methods provided
herein can be used to ligate the left atrial appendage.
Inventors: |
Friedman; Paul A.;
(Rochester, MN) ; Bruce; Charles J.; (Rochester,
MN) ; Asirvatham; Samuel J.; (Rochester, MN) |
Correspondence
Address: |
MUETING, RAASCH & GEBHARDT, P.A.
P.O. BOX 581336
MINNEAPOLIS
MN
55458-1336
US
|
Assignee: |
Mayo Foundation for Medical
Education and Research
Rochester
MN
|
Family ID: |
39156684 |
Appl. No.: |
12/442294 |
Filed: |
September 21, 2007 |
PCT Filed: |
September 21, 2007 |
PCT NO: |
PCT/US07/20509 |
371 Date: |
October 28, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60826413 |
Sep 21, 2006 |
|
|
|
Current U.S.
Class: |
606/144 |
Current CPC
Class: |
A61B 2017/00867
20130101; A61B 17/12013 20130101; A61B 18/1492 20130101; A61B
2017/00243 20130101; A61B 2017/00575 20130101 |
Class at
Publication: |
606/144 |
International
Class: |
A61B 17/04 20060101
A61B017/04 |
Claims
1. A ligating device comprising: a catheter comprising a proximal
end and a distal end; a ligating element located within the
catheter, wherein the ligating element comprises a lumen and a
first end and a second end, wherein the first end and the second
protrude from the proximal end of the catheter; and a control
element located within the lumen of the ligating element, the
control element comprising a first end that protrudes from the
first end of the ligating element, wherein a distal portion of the
control element forms an open loop upon exit from the distal end of
the catheter, and wherein the open loop is compressed when the
distal portion of the control element is located within the
catheter, and further wherein the control element forces the
ligating element to adopt a lariat configuration when outside of
the catheter.
2. A ligating device according to claim 1, wherein the control
element is removable, such that the control element can be pulled
out of the lumen of the ligating element.
3. A ligating device according to claim 1, wherein the control
element comprises a second end, and wherein the second end of the
control element protrudes from the ligating element.
4. A ligating device according to claim 1, wherein a portion of the
ligating element comprises a knot formed therein.
5. A ligating device according to claim 4, wherein the control
element extends through the portion of the ligating element that
comprises the knot.
6. A ligating device according to claim 1, wherein the control
element comprises a distal portion and a proximal portion, and
further wherein the distal portion is thinner than the proximal
portion.
7. A ligating device according to claim 1, wherein the ligating
element comprises a knot formed therein, and wherein the control
element comprises a distal end that is located distal from the
knot.
8. A ligating device according to claim 7, wherein a secondary
control element is located within a portion of the ligating
element, wherein a distal end of the second control element is
located proximal from the knot such that the second control element
does not extend through the knot.
9. A ligating device according to claim 1, wherein the ligating
element comprises a hollow suture and the control element comprises
shape memory material.
10. A ligating device according to claim 1, wherein the lariat is
formed at an angle with respect to an elongate portion of the
control element from which the lariat extends.
11. A ligating device according to claim 1, wherein the control
element comprises an angled portion when the control element is
located outside of the catheter.
12. A ligating device according to claim 1, further comprising a
positioning element attached to the lariat of the ligating
element.
13. A ligating device according to claim 1, further comprising an
appendage positioning element.
14. A ligating device according to claim 1, wherein control element
comprises magnetizable material such that the position of the
ligating element can be manipulated by a magnetic device.
15. A ligating device according to claim 1, further comprising a
sheath in which the catheter is located.
16. A ligating device comprising: a catheter comprising a proximal
end and a distal end; an elongate element located within the
catheter, the elongate element comprising a proximal end and a
distal end; a ligating element located within the catheter, wherein
the ligating element is attached to the distal end of the elongate
element, and further wherein the ligating element comprises an
original shape of a closed loop; a control element located within
the catheter, the control element comprising a first end that
protrudes from the proximal end of the catheter, wherein a portion
of the control element is contained within the ligating element,
wherein pulling on the first end of the control element opens the
ligating element from its original closed loop shape to open the
ligating element into a lariat configuration.
17. A ligating device according to claim 16, wherein the ligating
element is rotatably attached to the elongate element.
18. A ligating device comprising: a catheter comprising a proximal
end and a distal end; an elongate element located within the
catheter, the elongate element comprising a proximal end and a
distal end; a ligating element located within the catheter, wherein
the ligating element is attached to the distal end of the elongate
element, and further wherein the ligating element comprises a ring
clip whose natural position is closed; a hollow control element
attached to the ligating element; and a conduit in fluid
communication with the hollow control element, wherein the conduit
extends to the proximal end of the catheter, wherein pressurized
fluid delivered to the control element inflates the control element
to open the ligating element.
19. A ligating device according to claim 18, wherein the control
element is located inside of the ligating element.
20. A ligating device according to claim 18, wherein the control
element is located outside of the ligating element.
21. A ligating device according to claim 18, wherein the conduit is
located within the elongate element.
22. A ligating device according to claim 18, further comprising a
source of pressurized fluid in fluid communication with the
conduit.
23. A ligating device comprising: a catheter comprising a proximal
end and a distal end; a control element located within the
catheter, wherein the control element comprises an elongate U-shape
with both ends protruding from the proximal end of the catheter and
the bottom of the U-shape positioned near the distal end of the
catheter; a ligating element attached to one end of the control
element; wherein the end of the control element that is not
attached to the ligating element can be pulled to advance the
ligating element through the catheter.
24. A ligating device according to claim 23, wherein the ligating
device further comprises a tubular sheath surrounding a portion of
the control element at the distal end of the catheter, wherein
advancing the ligating element also advances the ligating element
through the tubular sheath.
25. A ligating device comprising: a catheter comprising a proximal
end and a distal end; a control element located within the
catheter, the control element comprising a first elongate portion
located within the catheter, the first elongate portion comprising
a proximal end and a distal end, wherein the control element
further comprises a second elongate portion located within the
catheter, the second elongate portion comprising a proximal end and
a distal end; and a ligating element attached to the distal ends of
the first elongate portion and the second elongate portion, wherein
manipulation of the first elongate portion and the second elongate
portion cause the ligating element to form a lariat.
26. A method of ligating an anatomical structure, the method
comprising: advancing a ligating device according to claim 1 to a
selected anatomical structure; and operating the ligating device to
ligate the selected anatomical structure.
27-30. (canceled)
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/826,413, filed on Sep. 21, 2006 and
titled DEVICES AND METHODS FOR LIGATING ANATOMICAL STRUCTURES,
which is hereby incorporated by reference in its entirety.
[0002] The present invention relates to devices and methods for
ligating anatomical structures such as, e.g., the left atrial
appendage.
[0003] Atrial fibrillation is a common cardiac rhythm disorder
affecting more than two million people each year, in which the
upper part of the heart beats more quickly than the rest of the
heart. This phenomenon is due to the generation of erratic or extra
electrical signals that cause the top part of the heart to
fibrillate rapidly and irregularly. The adult human heart normally
beats 60 to 80 times per minute at rest. With atrial fibrillation,
the heart can beat as many as 300 to 600 times a minute.
[0004] One of the most significant dangers from atrial fibrillation
is stroke. In fact, atrial fibrillation can make stroke as much as
five times more likely than in the general population. Since the
heart does not pump normally or efficiently during atrial
fibrillation, blood can pool and stagnate in the atria, resulting
in clot formation.
[0005] Blood pooling and clot formation is especially likely to
occur in the left atrial appendage (LAA). The LAA is a hollow,
pedunculated extension that resembles a small windsock formed off
the lateral wall of the left atrium. The LAA usually contracts with
the rest of the left atrium during normal heart function, thereby
continually moving blood throughout the hollow extension. During
atrial fibrillation, however, the LAA often fails to contract,
thereby allowing blood to pool and stagnate inside the appendage.
As a result, thrombus or clot formation can occur. Such clots can
be ejected from the LAA into the left atrium and left ventricle,
and then can be released into the bloodstream to become potential
obstructions in the brain or in other vascular structures.
SUMMARY
[0006] The present invention provides methods and devices for
ligating anatomical structures, where anatomical structures include
both those that are purely anatomical and those that are
pathological. In some instances, the structures are ligated to,
e.g., reduce or prevent blood clot formation in and release from a
structure such as the LAA. These methods and devices can be used to
ligate the LAA, thus preventing blood from entering the appendage,
pooling, and forming clots. Ligation of the LAA also can prevent or
reduce the escape of previously formed clots into the bloodstream.
The methods and devices provided herein can facilitate minimally
invasive treatment for atrial fibrillation. These methods can be
performed in conjunction with other procedures (e.g., mitral valve
replacement, radiofrequency ablation, atrial fibrillation ablation,
coronary artery bypass, etc.) or they can be performed solely to
ligate the anatomical structure (such as the LAA).
[0007] Although the exemplary devices and methods described herein
focus on ligation of the LAA, the devices and methods of the
present invention can be useful for ligation of other anatomical
structures, including, e.g., the gallbladder, the GI appendage,
diverticuli, fallopian tubes or ovaries, vascular aneurysms, or any
other pedunculated structure or mass. The devices can be used in
any laparoscopic or minimally invasive surgery in which it would be
useful to ligate, tie, or clip a structure via a single port
access.
[0008] In one aspect, the present invention provides a ligating
device that includes a catheter having a proximal end and a distal
end; a ligating element located within the catheter, wherein the
ligating element includes a lumen and a first end and a second end,
wherein the first end and the second protrude from the proximal end
of the catheter; and a control element located within the lumen of
the ligating element, the control element including a first end
that protrudes from the first end of the ligating element, wherein
a distal portion of the control element forms an open loop upon
exit from the distal end of the catheter, and wherein the open loop
is compressed when the distal portion of the control element is
located within the catheter, and further wherein the control
element forces the ligating element to adopt a lariat configuration
when outside of the catheter.
[0009] In various embodiments, the ligating devices described
herein may include one or more of the following features: the
control element may be removable, such that the control element can
be pulled out of the lumen of the ligating element; the control
element may include a second end that protrudes from the ligating
element; a portion of the ligating element may include a knot
formed therein; the control element may extends through the portion
of the ligating element that includes a knot; and the control
element may include a distal portion and a proximal portion, and
the distal portion may be thinner than the proximal portion; the
ligating element may be a hollow suture and the control element may
include shape memory material; the lariat may be formed at an angle
with respect to an elongate portion of the control element from
which the lariat extends; the control element may include an angled
portion when the control element is located outside of the
catheter; a positioning element may be attached to the lariat of
the ligating element; the ligating device may include an appendage
positioning element; the control element may include magnetizable
material such that the position of the ligating element can be
manipulated by a magnetic device; and a sheath may be provided in
which the catheter is located; etc.
[0010] In still other embodiments, the ligating devices may include
one or more of the following features: the ligating element may
include a knot formed therein and the control element may have a
distal end that is located distal from the knot; a secondary
control element may be located within a portion of the ligating
element, wherein a distal end of the second control element may be
located proximal from the knot such that the second control element
does not extend through the knot; etc.
[0011] In another aspect, the present invention may provide a
ligating device that includes a catheter having a proximal end and
a distal end; an elongate element located within the catheter, the
elongate element having a proximal end and a distal end; a ligating
element located within the catheter, wherein the ligating element
is attached to the distal end of the elongate element, and further
wherein the ligating element comprises an original shape of a
closed loop; a control element located within the catheter, the
control element including a first end that protrudes from the
proximal end of the catheter, wherein a portion of the control
element is contained within the ligating element, wherein pulling
on the first end of the control element opens the ligating element
from its original closed loop shape to open the ligating element
into a lariat configuration. The ligating element may be rotatably
attached to the elongate element.
[0012] In another aspect, the present invention may provide a
ligating device that includes a catheter having a proximal end and
a distal end; an elongate element located within the catheter, the
elongate element having a proximal end and a distal end; a ligating
element located within the catheter, wherein the ligating element
is attached to the distal end of the elongate element, and further
wherein the ligating element includes a ring clip whose natural
position is closed; a hollow control element attached to the
ligating element; and a conduit in fluid communication with the
hollow control element, wherein the conduit extends to the proximal
end of the catheter, wherein pressurized fluid delivered to the
control element inflates the control element to open the ligating
element. The ligating device may further include one or more of the
following features: the control element may be located inside or
outside of the ligating element; the conduit may be located within
the elongate element; a source of pressurized fluid may be in fluid
communication with the conduit; etc.
[0013] In another aspect, the present invention may provide a
ligating device that includes a catheter having a proximal end and
a distal end; a control element located within the catheter,
wherein the control element has an elongate U-shape with both ends
protruding from the proximal end of the catheter and the bottom of
the U-shape positioned near the distal end of the catheter; and a
ligating element attached to one end of the control element;
wherein the end of the control element that is not attached to the
ligating element can be pulled to advance the ligating element
through the catheter. The ligating device may include a tubular
sheath surrounding a portion of the control element at the distal
end of the catheter, wherein advancing the ligating element also
advances the ligating element through the tubular sheath.
[0014] In another aspect, the present invention provides a ligating
device that includes a catheter having a proximal end and a distal
end; a control element located within the catheter, the control
element having a first elongate portion located within the
catheter, the first elongate portion including a proximal end and a
distal end, wherein the control element further includes a second
elongate portion located within the catheter, the second elongate
portion having a proximal end and a distal end; and a ligating
element attached to the distal ends of the first elongate portion
and the second elongate portion, wherein manipulation of the first
elongate portion and the second elongate portion cause the ligating
element to form a lariat.
[0015] In another aspect, the present invention provides a method
of ligating an anatomical structure that includes advancing a
ligating device as described herein to a selected anatomical
structure; and operating the ligating device to ligate the selected
anatomical structure.
[0016] In another aspect, the present invention provides a tissue
piercing device that includes a hollow sheath; and a wire disposed
within the hollow sheath, wherein the wire includes a distal end
configured to coil after being deployed out of the sheath. The
tissue piercing device may further include a hollow needle
contained within the hollow sheath, wherein the wire is disposed
within the hollow needle.
[0017] In another aspect, the present invention provides a tissue
piercing device that includes a hollow sheath; and a wire disposed
within the hollow needle, wherein the wire includes an RF tip at
its distal end. The tissue piercing device may further include a
hollow needle contained within the hollow sheath, wherein the wire
is disposed within the hollow needle.
[0018] In another aspect, the present invention can provide a
device that includes a hollow flexible catheter having a proximal
end and a distal end; an elongate ligating element disposed within
the catheter, wherein the ligating element has a first end and a
second end that protrude from the proximal end of the catheter; and
an elongate control element disposed within the ligating element,
wherein the control element has a first end and a second end that
are positioned toward the proximal end of the catheter, wherein at
least one of the first and second ends of the control element
protrudes from an end of the ligating element, wherein the control
element comprises shape memory material, and wherein at least a
portion of the control element is shaped to form an open loop upon
exit from the distal end of the catheter.
[0019] The ligating element can be in the form of a hollow suture.
The suture can include materials such as, e.g., PTFE, polyethylene,
or polypropylene. The control element can include shape memory
materials such as, e.g., Nitinol. The loop formed by the control
element can be at an angle with respect to another portion of the
control element. The control element can further form an angled
section upon exit from the distal end of the catheter. The device
can potentially have a length between about 12 inches and about 60
inches (e.g., between about 36 inches and about 48 inches). The
device can potentially have a diameter between about 0.05 cm and
about 3 cm (e.g., between about 0.1 cm and about 0.4 cm). The
device can further include a positioning element disposed within
the catheter, a sheath in which the catheter is disposed, and/or an
appendage positioning element.
[0020] In another aspect, the present invention can provide a
device that includes a hollow flexible catheter having a proximal
end and a distal end; an elongate element disposed within the
catheter, wherein the elongate element has a proximal end extending
from the proximal end of the catheter and distal end positioned
near the distal end of the catheter; a rigid ligating element
attached to the distal end of the elongate element, wherein the
ligating element includes shape memory material configured in a
closed loop; and a flexible control element disposed within the
catheter and contained within at least a portion of the ligating
element, wherein the control element has a first end and a second
end, wherein at least one of the first and second ends of the
control element protrudes from the proximal end of the
catheter.
[0021] The ligating element can include a shape memory material
such as, e.g., Nitinol. The ligating element can be rotatably
attached to the elongate element. The ligating element and the
elongate element can be attached via a pin, about which the
ligating element can rotate with respect to the elongate element.
The ligating element can include atraumatic material (e.g., PTFE or
DACRON.TM.). The control element can include, e.g., a suture, a
string, a flexible wire, etc. The device can, e.g., have a length
between about 12 inches and about 60 inches (e.g., between about 36
inches and about 48 inches). The device can, e.g., have a diameter
between about 0.05 cm and about 3 cm (e.g., between about 0.1 cm
and about 0.4 cm). The device can further include a positioning
element disposed within the catheter, a sheath in which the
catheter is disposed, and/or an appendage positioning element.
[0022] In another aspect, the present invention may provide a
device that includes a hollow flexible catheter having a proximal
end and a distal end; an elongate element disposed within the
catheter, wherein the elongate element has a proximal end extending
from the proximal end of the catheter and a distal end positioned
near the distal end of the catheter; a flexible, hollow,
donut-shaped control element attached to the distal end of the
elongate element, wherein the control element has an outer surface
and an inner lumen; and a rigid ligating element contained within
or positioned around the ligating element, wherein the ligating
element includes shape memory material and is in the form of a
closed loop.
[0023] The elongate element can define a lumen between the proximal
and distal ends, and wherein the lumen of the elongate element is
in fluid communication with the lumen of the control element. The
control element can include, e.g., PTFE, polyethylene, or
polypropylene. The ligating element can include shape memory
materials such as, e.g., Nitinol. The device can, e.g., have a
length between about 12 inches and about 60 inches (e.g., between
about 36 inches and about 48 inches). The device can, e.g., have a
diameter between about 0.05 cm and about 3 cm (e.g., between about
0.1 cm and about 0.4 cm). The device can further include a
positioning element disposed within the catheter, a sheath in which
the catheter is disposed, and/or an appendage positioning
element.
[0024] In still another aspect, the present invention may provide a
device that includes an elongate, hollow, flexible sheath having a
tapered distal end; an elongate, hollow needle disposed within the
sheath; and an elongate wire disposed within the needle. The wire
can have a distal end, and may include a radiofrequency electrode
at the distal end. The hollow needle can have a curved distal end.
The device can further include means for advancing a portion, of
the wire out of the distal end of the sheath. The wire can have a
distal end configured to coil after being advanced out of the
distal end of the sheath.
[0025] The present invention may also provide a method for
accessing the pericardial space of a subject. The method can
include passing a device as described herein through the
circulatory system and into the left coronary sinus of the subject;
and piercing the wall of the coronary sinus or coronary venous
system of the subject to access the pericardial space.
[0026] In another aspect, the present invention may provide a
method for ligating the left atrial appendage in a subject. The
method can include advancing the distal end of a ligation device as
described herein into the chest of the subject; placing the distal
end of the device within the pericardium of the subject; and
positioning the ligating element around the base of the left atrial
appendage. The distal end can he advanced into the chest of the
subject via a suprasternal, intercostal, or sub-xiphoid approach.
The distal end can also be advanced through the coronary sinus or
one of its tributaries into the pericardial space.
[0027] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention pertains.
Although methods and materials similar or equivalent to those
described herein can be used to practice the invention, suitable
methods and materials are described below. All publications, patent
applications, patents, and other references mentioned herein are
incorporated by reference in their entirety. In case of conflict,
the present specification, including definitions, will control. In
addition, the materials, methods, and examples are illustrative
only and not intended to be limiting.
[0028] The words "preferred" and "preferably" as used herein refer
to embodiments of the invention that may afford certain benefits,
under certain circumstances. However, other embodiments may also be
preferred, under the same or other circumstances. Furthermore, the
recitation of one or more preferred embodiments does not imply that
other embodiments are not useful, and is not intended to exclude
other embodiments from the scope of the invention.
[0029] As used herein, "a," "an," "the," "at least one," and "one
or more" are used interchangeably. Thus, for example, a ligating
element can include one or more ligating elements The term "and/or"
means one or all of the listed elements or a combination of any two
or more of the listed elements.
[0030] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and the description below.
Other features and advantages of the invention will be apparent
from the description and drawings, and from the claims.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0031] FIG. 1 is a cross-sectional view of the distal portion of a
ligating device having a catheter with a hollow suture ligating
element and a control element contained within the hollow suture
ligating element, where the ligating and control elements are in a
closed configuration.
[0032] FIG. 2 is a cross-sectional view of the distal portion of
the device shown in FIG. 1, wherein the ligating and control
elements are in an open configuration, forming a lariat or
loop.
[0033] FIG. 3 is a cross-sectional/perspective view of the distal
portion of a device having a lariat or loop oriented at an angle
relative to the elongate portion of the ligating and control
elements.
[0034] FIGS. 4A and 4B are cross-sectional/perspective views of the
distal portion of devices having a lariat or loop oriented at an
angle relative to the elongate portion of the ligating and control
elements, and further having an elongate element with an angled
portion.
[0035] FIGS. 5A and 5B are cross-sectional views of the distal
portion of devices having a catheter with a ligating element and a
control element contained therein, and further having an outer
sheath with a positioning element contained therein. The
positioning element is shown at the base of the lariat or loop
(FIG. 5A) or at the distal end of the lariat or loop (FIG. 5B).
[0036] FIG. 6 is a cross-sectional/perspective view of the distal
portion of a device as shown in FIG. 3, where the device further
includes an appendage positioning device contained within the
catheter.
[0037] FIG. 7 is a cross-sectional view of the distal portion of
the device as shown in FIG. 2, further depicting removal of the
control element.
[0038] FIG. 8 is a cross-sectional view of the distal portion of
the device as shown in FIG. 2, further depicting a knot in the
ligating element.
[0039] FIG. 9 is a cross-sectional view of the distal portion of
the device as shown in FIG. 8, where the knot is advanced to the
base of the lariat and the lariat is in a tightened
configuration.
[0040] FIG. 10 is a cross-sectional view of the distal portion of
the device as shown in FIG. 9, further including a repositioning
element and depicting loosening of the knot.
[0041] FIG. 10A is a cross-sectional view of a ligating device in
which the control element is positioned through a knot formed in
the ligating element.
[0042] FIG. 10B is a cross-sectional view of a ligating device in
which two control elements are positioned in the ligating
element.
[0043] FIG. 11 is a side view of the distal portion of a device
having a catheter and a rigid ligating element, where the ligating
element is connected to an elongate element contained within the
catheter, and further having a control element extending through
the catheter and the ligating element. As shown, the ligating
element is in a closed configuration.
[0044] FIG. 12 is a cross-sectional view of the distal portion of
the device depicted in FIG. 11, with the ligating element in a
closed configuration.
[0045] FIGS. 13A and 13B are cross-sectional views of the distal
portion of devices having a control element extending through the
entire ligating element (FIG. 13A) or through a portion of the
ligating element (FIG. 13B), with the ligating element shown in an
open configuration.
[0046] FIG. 14 is a side view of a portion of the distal end of the
device depicted in FIG. 13, where the device further includes a
positioning element.
[0047] FIG. 15 is a side view of a portion of the distal end of the
device depicted in FIG. 13, where the device further includes a
positioning element, and where the ligating element is at an angle
with respect to the elongate element.
[0048] FIG. 16 is a cross-sectional view of the distal portion of a
device having a catheter containing an elongate element, with a
hollow control element connected to the elongate element, and a
rigid ligating element contained within the hollow control element.
The control and ligating elements arc shown in a closed (e.g.,
uninflated) configuration.
[0049] FIG. 17 is a cross-sectional view of the distal portion of
the device shown in FIG. 16, where the control and ligating
elements are in an open (e.g., inflated) configuration.
[0050] FIG. 18 is a cross-sectional view of the distal portion of
the device shown in FIG. 17, where the device further includes a
positioning element.
[0051] FIG. 19 is a cross-sectional view of the distal portion of a
device having a control element that includes two substantially
rigid elongate portions, and a flexible ligating element attached
to the distal ends of the elongate portions.
[0052] FIG. 20 is a cross-sectional view of the distal portion of
the device of FIG. 19, where the elongate portions of the control
element have been manipulated such that the flexible ligating
element forms a lariat.
[0053] FIG. 21 is a cross-sectional view of the distal portion of a
device having a catheter, a control element, and a protective
sheath.
[0054] FIG. 22 is a cross-sectional view of the distal portion of
the device of FIG. 21, with the control element pulled through the
catheter such that a ligating element connected to the control
element is advanced through the protective sheath.
[0055] FIG. 23 is a cross-sectional view of the distal portion of a
device for accessing the pericardial space through the coronary
sinus (CS).
[0056] FIG. 24 is a side view of the distal end of a wire that
coils when deployed through the CS wall.
[0057] FIG. 25 is a cross-sectional view of the distal portion of
the device of FIG. 23, having a needle with a curved distal
end.
[0058] FIG. 26 is a cross-sectional view of the distal portion of
the device shown in FIG. 25, further including a balloon connected
to a fluid conduit.
[0059] FIG. 27 is a cross-sectional view of the distal portion of
the device of FIG. 25, having a wire with a radiofrequency (RF)
electrode at its tip.
[0060] FIG. 28 is a cross-sectional view of the distal portion of a
device for accessing the pericardial space through the CS, where
the device contains a catheter having suture needles disposed
therein.
[0061] Like reference symbols in the various drawings indicate like
elements.
DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0062] The devices and methods provided in connection with the
present invention can be used to ligate anatomical structures such
as, e.g., the LAA and other anatomical features. Although the
exemplary embodiments described herein are discussed in the context
of LAA ligation, the devices and methods of the present invention
should not be limited to that use. Ligation of anatomical
structures may be performed for a variety of reasons. Ligation of
the LAA may, for example, reduce the likelihood of or prevent clots
from forming in the LAA and/or reduce the likelihood of or prevent
previously formed clots from escaping into the bloodstream.
[0063] In general, the ligating devices of the present invention
may include a ligating element and a control element. The control
element can be contained within the ligating element or the
ligating element can be contained within the control element. In
other embodiments, the ligating element can be separate from the
control element. For example, the ligating element can encircle the
control element, or vice versa, or an end of the ligating element
(e.g., a length of suture) can he attached to an end of the control
element (e.g., a length of wire), such that neither element is
contained within the other.
[0064] The ligating element, the control element, or both the
ligating element and the control element can be contained within
the lumen of a catheter having proximal and distal ends, with the
lumen defined therebetween. At least a portion of the ligating
element and/or at least a portion of the control element can be
positioned at the distal end of the catheter. In some embodiments,
the ligating element and/or the control element can extend through
the length of the catheter. In other embodiments, the ligating
element and/or the control element can be positioned at the end
(e.g., the distal end) of a separate elongate element, such that
the elongate element extends through the length of the catheter and
the ligating and/or control elements are positioned at the distal
end of the catheter. For example, in some cases the ligating
element can be positioned at the distal end of an elongate element
within the catheter, and the control element can extend through all
or a portion of the ligating element and through the length of the
catheter.
[0065] The ligating element can be adapted for placement around the
LAA (e.g., the base of the LAA) or other anatomical structure, such
that the LAA can be effectively closed off from the left atrium.
The control element can be adapted to facilitate placement of the
ligating element in the desired position around the LAA. Typically,
at least one of the ligating element or the control element can be
constructed to be rigid and/or to have shape memory, such that the
ligating element and/or control element can have a closed
configuration for passage through the catheter and eventual
tightening around the base of the LAA, and an open "lariat"
configuration for placement over and around the body of the
LAA.
[0066] The lariat formed by the ligating element and/or control
element in the open configuration can have any suitable shape and
size. For example, a lariat can have an essentially circular or
oval shape, or can have an irregular shape to, for example, follow
the curve of the heart. A lariat can have a maximum diameter from,
e.g., about 0.5 cm to about 4 cm (e.g., from about 0.7 cm to about
3.5 cm, from about 1.0 cm to about 2.5 cm, or from about 1.5 cm to
about 2.0 cm).
[0067] The ligating devices provided in connection with the present
invention may be readily deployed in a percutaneous manner. In
addition, the ligating devices can be adapted to minimize trauma to
the tissue they contact such that there is little or no erosion
through the tissue, reducing the likelihood of bleeding and cardiac
tamponade. Further, the devices can be reversible and/or
repositionable, such that a clinician can position the ligating
element over the LAA, tighten the ligating element around the LAA,
and then loosen and reposition the ligating element if desired.
[0068] In some embodiments, a ligating device can have a hollow
ligating element formed of a soft, pliable material (e.g.,
polytetrafluoroethylene (PTFE), polyethylene, polypropylene, or any
other suitable material), and an inner control element formed of a
more rigid material (e.g., wire, etc.) or any other suitable
material that can provide the hollow element with at least
temporary rigidity (e.g., pressurized fluid such as water or
air).
[0069] For example, a ligating element can be in the form of a
hollow (e.g., PTFE) suture, with a control element running through
the lumen of the hollow suture. The wire loaded suture can have a
generally elongate "U" shape and can extend through the length of
the catheter, with both ends protruding from the proximal end of
the catheter and the bottom of the "U" positioned at or near the
distal end of the catheter. The distal end of the device can be
positioned near the LAA (or other anatomical structure) via any
suitable approach (e.g., via sub-xyphoid, intercostal, or
trans-coronary sinus approach for the LAA). The ligating element
can be passed through the distal end of the catheter and placed
around the base of the LAA.
[0070] In some embodiments, the inner control element can be made
of a shape memory material (e.g., Nitinol), such that when the
hollow ligating element exits the distal end of the catheter it
assumes an open "lariat" configuration to facilitate placement
around the LAA or other anatomical structure. The inner control
element may also give the ligating element a configuration that
places (orients) the lariat at an angle with respect to the
elongate portion of the ligating element, to further facilitate
positioning of the device over the LAA or other anatomical
structure. In some embodiments, the control element can be
configured such that as the ligating element is progressively
extended out of the distal end of the catheter, the shape and
angulation of the lariat changes. The angulation and shape of the
ligating device can, in some embodiments, be tailored based on
patient anatomy. Angled configurations of the control element can
provide additional control of the lariat, to further facilitate
positioning of the device.
[0071] In addition, a ligating device provided in connection with
the present invention may include a separate positioning element,
which also can be used to position and reposition or remove the
ligating element if desired. A clinician also can manipulate either
or both ends of the inner control element to alter the shape and/or
position of the ligating element. In some embodiments, the control
element can contain a magnetizable material (e.g., iron, nickel,
cobalt, gadolinium, dysprosium, or composites of flexible resins
and magnetic powders, with or without a binder such as vinyl), and
the position of the ligating element can be manipulated by a
magnetic device outside the body (e.g., a magnetic navigation
system from, for example, Stereotaxis, Inc. of St. Louis, Mo.).
[0072] Once placed, the ligating element can be retained in
position via a clip or any other suitable means. The control
element can be removed if desired (e.g., by pulling on one end of
the control element such that it slides out of the lumen in the
ligating element). Once the control element is removed, the
ligating element can be tightened to close the LAA and then fixed
in position via a clip, a knot, or any other suitable fastening
means.
[0073] If a knot is used, the knot can be tied outside the body and
pushed through the catheter into position to close the LAA.
Examples of suitable knot pushing devices and methods are described
in, for example, U.S. Pat. Nos. 6,132,439, 5,759,189, and
5,769,863. A knot pushing device can be made from a substantially
rigid material, from a flexible material (e.g., polypropylene or
polyethylene), or from a combination of flexible and rigid
materials.
[0074] In some embodiments, a ligating device of the present
invention can have a ligating element formed of a rigid material
(e.g., shape memory material such as Nitinol, etc.), and an inner
or outer control element formed of a pliable material (e.g.,
suture, soft wire, or any other suitable material). The ligating
element can be positioned at the end of an elongate element that
extends through the length of the catheter, such that the ligating
element can be positioned at or toward the distal end of the
device, within the lumen of the catheter.
[0075] The rigid (e.g., shape memory) material of the ligating
element can be covered on its exterior surface with a coating
(e.g., PTFE, DACRON.TM., or other suitable material) to, for
example, prevent tissue trauma. Examples of suitable coatings are
described elsewhere (e.g., U.S. Publication No. 2005/0277959).
[0076] In some cases, the natural position or configuration of the
ligating element can be closed. Such a position or configuration
can facilitate passage of the ligating and control elements through
the catheter, and can provide a ready means to close off the LAA
after placement of the ligating element.
[0077] An inner control element can extend through the entire
length of the ligating element or through a portion of the ligating
element. An outer control element can extend around (e.g.,
encircle) the entire ligating element, or can be attached to a
portion of the ligating element. In some embodiments, a control
element can be secured at or near the distal end of the ligating
element.
[0078] In use, a clinician can pull on the control element in the
proximal direction, opening the ligating element into a lariat
configuration to allow for positioning of the device over the LAA.
In some cases, an inner control element extending through the
entire length of a ligating element may not be secured within the
ligating element, but can be configured such that a clinician can
apply force in the proximal direction (e.g., by pulling on both
ends of the control element) to open the ligating element. The
ligating element can have a pre-formed shape that, for example,
facilitates opening of the lariat upon actuation of the control
element. For example, a ligating element containing a shape-memory
material can have a preformed shape with preferential bends to
facilitate formation of a lariat.
[0079] In some cases, a portion of the ligating element (e.g., at a
point on the base of one side of the ligating element) can be
affixed to the distal end of the catheter or the sheath. In these
cases, the control element can be actuated (e.g., pulled in the
proximal direction) such that the unaffixed side of the ligating
element can move into the catheter, causing the affixed side to
bend, thus forming a loop. In some embodiments in which a portion
of the ligating element is affixed to the distal end of the
catheter, the unaffixed side of the ligating element can be
magnetized. In such embodiments, a clinician can use a magnet or
magnetic system outside the subject's body to manipulate the
ligating element and pull the unaffixed, magnetized side of the
ligating element into the catheter, thus causing the ligating
element to form a lariat. In some cases in which a portion of the
ligating element is magnetized, a device may lack a separate
control element.
[0080] Once the ligating element is in position, the control
element can be released to close the ligating element. The ligating
element can be separated from the elongate element and, in some
cases, from all or a portion of the control element. Any suitable
means can be used to separate the ligating element from other
elements of the device. An inner control element can be left
entirely or partially inside the ligating element. An outer control
element can be entirely or partially removed from the ligating
element.
[0081] In some embodiments, a rigid ligating element can be
connected to an elongate element by a pin or other mechanism at its
base to, for example, allow a clinician to adjust the angle of the
ligating element with respect to the elongate element (e.g., once
the ligating element has been advanced beyond the distal end of the
catheter). The ability to manipulate the angle of the ligating
element can facilitate positioning of the ligating element over the
LAA.
[0082] In some embodiments, a device can include a ligating element
in the form of a ring clip (e.g., manufactured of shape memory
wire) whose natural position is closed, and a hollow, donut-shaped
control element comprising a soft pliable material (e.g., PTFE,
polyethylene, or polypropylene) that is air tight. In some
embodiments, the ring clip can be contained within the control
element. For example, a ring clip (formed of, e.g., Nitinol) can be
contained within a hollow ring (of, e.g., PTFE). In some cases, the
ring clip can encircle the outer circumference of the control
element. For example, a ring clip (formed of, e.g., Nitinol) can
encircle a hollow ring (of, e.g., PTFE). The device can be deployed
by advancing the ligating element (ring clip) and the control
element out of the distal end of the catheter, inflating the
control element (e.g., with a gas or a liquid) to open the ring
clip, positioning the device at the base of the LAA, and deflating
the control element to close the ring clip. In such embodiments,
the control element can provide an atraumatic covering for the
ligating element.
[0083] In some embodiments, a device can have an elongate rigid
control element (e.g., a wire) with a ligating element (e.g., a
suture) affixed to one end. The control element can extend through
the length of the catheter, e.g., with a generally elongate "U"
shape in which both ends protrude from the proximal end of the
catheter and the bottom of the "U" is positioned at or near the
distal end of the catheter. A clinician can manipulate the position
of the control element using, for example, a positioning element as
described herein, or using a magnet in cases where the control
element is magnetized. Once the control element is placed around
the LAA, the end of the control element that is not attached to the
ligating element can be pulled to advance the ligating element
through the catheter and around the LAA. When the ligating element
is in place around the base of the LAA, it can be fastened in place
(e.g., knotted or clipped), and any remaining portion of the
ligating element and the control element can be retracted from the
subject's body.
[0084] In some cases, the ligating device can include a protective
element. For example, the ligating device can include a hollow
tubular sheath that can surround a portion of the control element
at the distal end of the catheter, and can be placed around the LAA
(or other anatomical structure) along with the control element.
Such a sheath can protect the tissue from frictional damage as the
control element is pulled through the catheter and the suture is
positioned around the LAA (or other anatomical structure). A
protective element also can distribute the force of the suture over
a greater area of the LAA.
[0085] In some embodiments, a ligating device of the present
invention can include a control element having two rigid elongate
portions (e.g., two lengths of wire extending through the catheter)
with a flexible ligating element attached to the ends of the
control element closest to the distal end of the catheter. By
manipulating the elongate portions of the control element with
respect to one another, a clinician can cause the flexible ligating
element to form a lariat that can be placed around the LAA (or
other anatomical structure). A fastening means (e.g., a clip) can
be passed through the catheter (e.g., along one or both portions of
the control clement) to retain the ligating element around the base
of the LAA. Once the lariat is in place, a clinician can cut any
excess portion of the ligating element, and remove the device from
the subject's body.
[0086] Ligating devices of the present invention can include one or
more additional elements to assist with positioning of the ligating
element and/or the LAA (or other anatomical structure). These
additional elements can, e.g., be contained within the catheter or
within an outer sheath that also contains the catheter. Positioning
elements can be deflecting and/or steerable to, for example,
facilitate their positioning within a device.
[0087] Appendage positioning elements can include, for example,
suction catheters, forceps, and cryogenic-tipped catheters, which
can be used to lift and hold the LAA while the lariat is put into
position at its base. See, e.g., U.S. Patent Application
Publication Nos. 2005/0154404 and 2004/0030335, as well as U.S.
Pat. No. 6,488,689. An appendage control device can be, for
example, a suction device, a grasper device, or a cryogenic device.
A suction device can lift and/or hold the LAA by applying a gentle
vacuum to the surface of the LAA, while a grasping device can
physically hold the LAA. A cryogenic appendage control device can
be, for example, a probe with a cooled tip that can attach to the
LAA like a tongue to a cold flag pole, and that can be warmed to
permit removal from the surface of the LAA with minimal trauma to
the tissue.
[0088] In addition or alternatively, a positioning element can be
used to help position and place the ligating element. A positioning
element can be rigid or at least substantially rigid, as in the
case of a rod comprising wire, plastic, or any other suitable
material. Alternatively, a positioning element can be flexible, as
in the case of a suture having a loop through the lariat. In some
cases, a positioning element can be releasably attached to the
lariat via any suitable means (e.g., threads, a pin, or a magnet),
or can include a hook at one end for grasping the lariat. The
positioning element can be used to push, pull, or otherwise
maneuver the lariat into position, and can remove the positioning
element from the lariat once the device is positioned around the
LAA. In some embodiments, a first lariat can be positioned around
the LAA, and then can be used as a positioning and/or control
element to facilitate placement of a second lariat around the base
of the LAA.
[0089] The ligating devices provided herein can have any suitable
length and width (e.g., diameter). For example, a device can have a
length between about 12 inches and about 72 inches (e.g., between
about 24 inches and 60 inches, between about 30 inches and about 54
inches, or between about 36 inches and about 48 inches), such that
its distal end can be placed within the pericardial space proximate
the LAA and its proximal end can be positioned outside a subject's
body. Further, a device can have any suitable diameter. For
example, a device can have an overall diameter (e.g., diameter of
the outer sheath, or diameter of the catheter if there is no outer
sheath) suitable for passage through the circulatory system and
into the coronary sinus, for passage between adjacent ribs, or for
sub-xiphoid passage. Thus, a device can have a diameter between
about 0.05 cm and about 1.5 cm, between about 0.1 cm and about 1.0
cm, between about 0.15 cm and about 0.5 cm, between about 0.2 cm
and about 0.4 cm, or about 0.2 cm, about 0.3 cm, or about 0.4 cm.
The device may be flexible to permit navigation through curved and
finite planes (such as the pericardial space) leading to the
anatomical structure (such as the LAA).
[0090] The ligating devices provided herein can be used in any
suitable type of minimally invasive approach. In some embodiments,
a ligating device can be used in an intercostal approach. For
example, a mini-thoracotomy procedure can be used in which the
distal end of a device can be inserted through a small incision
into the chest cavity and advanced between the ribs to the
pericardium. In some embodiments, a sub-xiphoid approach can be
used, in which the distal end of a device is inserted into the
chest cavity through a small incision and advanced between the
xiphoid process and adjacent intercostal cartilage until it reaches
the pericardium. In some cases, a suprasternal approach can be
used, in which the distal end of a device is inserted into the
chest cavity through a small incision above the sternum, and
advanced inferiorly toward the pericardium. For intracostal,
sub-xiphoid, and suprasternal approaches, the distal end of a
device can be advanced into the pericardial space through the
pericardium (i.e., from the exterior of the pericardium), and
positioned at or near the LAA.
[0091] In some embodiments, controlled exit from the coronary sinus
(CS) can be used. CS exit can be advantageous in that the angle of
approach can facilitate encircling the LAA at its base. In this
approach, a device (e.g., a tapered, flexible sheath or catheter)
can be passed into the coronary sinus via, for example, a femoral
vein, a jugular vein, or a subclavian vein. The sheath can have a
hollow needle and/or a wire contained therein when it is passed
into the CS, or a needle and/or wire can be passed through the
sheath after it reaches the CS. The tip of the device can be
positioned within the CS, and the distal end of the needle or wire
can be advanced through the wall of the CS and into the pericardial
space proximate the LAA. In some embodiments, the distal end of the
sheath or needle can be curved or angled, such that a wire
contained therein is directed to exit the needle toward the CS wall
rather than into the lumen of the CS. A similar approach discussed
herein could potentially be used to facilitate a controlled exit
from the right atrial appendage.
[0092] A device can include any suitable mechanism to facilitating
piercing of the CS wall. For example, the needle can contain a wire
that can be "cocked" with a spring mechanism. A clinician can
actuate the spring mechanism, and the resulting forward pressure
applied on the wire element can cause the needle or the wire within
the needle to pierce the CS wall. In some embodiments, the wire can
be configured such that once it enters the pericardial space, it
can curve and/or kink to prevent further advance of the needle
beyond the pericardial space. For example, a wire can be configured
to coil after piercing the CS wall, thus reducing the likelihood of
or preventing the end of the wire from puncturing the pericardial
sac or damaging the outer surface of the heart. In some cases, a
device can be configured such that the length of wire deployed from
the device is limited. For example, the length of wire that exits
the catheter or needle is limited to between about 0.5 mm and about
3 mm (e.g., about 0.5 mm, about 1 mm, about 1.5 mm, about 2 mm,
about 2.5 mm, or about 3 mm).
[0093] In some embodiments, a wire can have a RF electrode at its
tip. Thus, RF energy can be used to create an opening in the CS
wall for passage of the needle or catheter. The RF energy can be
turned off once the CS wall is pierced, to prevent puncture of the
pericardial sac. The sheath and/or the hollow needle can have an
angled or curved end, which can facilitate placement advancement of
the wire toward and through the CS wall.
[0094] Once the CS wall is pierced, the device (e.g., the sheath,
the needle, or the wire) can be advanced into the pericardial
space. The wire and, in some embodiments, the needle, can be
removed from the sheath, and a ligating device as described herein
can be passed through the sheath and advanced into the pericardial
space. In some embodiments, a RF ablation electrode can be passed
along or over the wire and into the pericardial space, and can be
used for pericardial mapping and/or ablation. A sheath and/or a
hollow needle having an angled or curved end can facilitate
placement of a ligating device or a RF electrode within the
pericardial space.
[0095] In some embodiments, a device can include a balloon that can
he deployed within the CS to prevent or reduce blood leakage into
the pericardial space, and/or to stabilize the device. The balloon
can be connected to a fluid conduit that extends through the
sheath, and through which a fluid such as air, oxygen, water, or
saline can be passed into the balloon. The balloon can be inflated
when the device is positioned within the CS, and can be deflated
prior to removal of the device from the CS.
[0096] After the LAA is ligated, the ligating device can be
removed. In some embodiments, the opening in the wall of the CS can
be closed. Any suitable technique can be used, including RF
ablation or physical closure using one or more hooks and/or
needles. For example, a RF-tipped wire can be passed through the
sheath or needle to the CS wall, and RF energy can be used to weld
the opening. In some cases, tissue at the opening in the CS wall
can be pulled into the distal end of the sheath or needle (e.g.,
using suction or a mechanical grasper), where it can be sutured
closed or welded together using RF energy. In some embodiments, a
balloon can be passed through the sheath to prevent or reduce blood
flow from the CS into the pericardial space.
[0097] To use the ligating devices provided herein, in general, a
clinician can position the distal end of a device provided herein
within the pericardial space proximate the LAA. The device, or a
portion thereof (e.g., the catheter) can be steerable using, for
example, conventional steerable sheath technology. A clinician can
advance the ligating element and control element out of the distal
end of the catheter.
[0098] A clinician can use the control element and/or a separate
positioning rod or suture to position the ligating element around
the LAA. In some embodiments, a separate appendage control device
as described herein can be used to lift and/or hold the LAA to
facilitate suitable placement of the ligating element. Positioning
elements can be deflecting and/or steerable. Whether or not a
separate control or positioning element is used, once the ligating
element is in position, the control element can be removed if
desired, and the ligating element can be tightened (around, e.g.,
the base of the LAA). It is noted that, while in most embodiments
the control element and the ligating element are passed through the
same device (e.g., the same catheter), control, ligating, and
positioning elements can be passed to the LAA through separate
devices, such that two or more pericardial access points can be
used.
[0099] Turning now to the figures, exemplary embodiments of
ligating devices in which the ligating element is in the form of a
pliable hollow material and the control element comprises a
shape-memory wire are depicted in FIGS. 1-10. Device 10 can include
catheter 20 with a proximal end (not shown) and distal end 25.
Catheter 20 can contain ligating element 30 and control element 40,
wherein control element 40 is disposed within the lumen of ligating
element 30. In these embodiments, ligating element 30 can be, for
example, a hollow suture, and control element 40 can be a wire.
Catheter 20 may be placed directly into the pericardial space, or
it may enter through a separate sheath already positioned with its
distal end in the pericardial space. In addition, the catheter
and/or sheath may be steerable. Although the devices are described
herein as exiting from the distal ends of the catheters, it should
be understood that the exit port through which the devices exit the
catheters may be located in the catheter sidewall proximate the
distal ends of the catheters or at the very tip of the catheters
(as depicted in, e.g., FIG. 2).
[0100] Control element 40 can be manufactured of shape-memory
material, and can be configured such that, for the portion of
control element 40 at distal end 25, the control element has an
"original" or "preferred" shape approximating a loop (e.g., a
circle or an oval). Thus, when control element 40 is contained
within catheter 20 as shown in FIG. 1 (in a closed configuration),
it can be compressed into a U-shape that is folded back on itself,
but when it is pushed out of distal end 25, it can expand to form
lariat 43 as shown in FIG. 2. As such, the loop configuration of
control element 40 forces ligating element 30 to adopt a lariat
(open) configuration suitable for positioning around, e.g., the
LAA. Additionally, preferentially pulling (proximal retraction) on
one or the other proximal end of the control elements may modify
the shape of the distal loop/lariat to assist with conformation to
anatomic variations.
[0101] In some embodiments, control element 40 can be configured
such that upon advancement past distal end 25 of the catheter 20,
the control element 40 assumes a shape in which lariat 43 is
oriented at an angle with respect to the elongate portion 46 of
control element 40. For example, as shown in FIG. 3, lariat 43 can
be at approximately a 90 degree angle with respect to elongate
portion 46 of control element 40. Lariat 43 can be at any suitable
angle with respect to elongate portion 46 (e.g., an angle of about
20, 30, 40, 45, 50, 60, 70, 80, 85, 90, 95, 100, 110, 120, 130,
135, 140, 145, or 150 degrees).
[0102] In addition or alternatively, the shape assumed by control
element 40 can include one or more angled portions, such as angled
portion 48 as shown in FIGS. 4A and 4B. Angled portion 48 can
further facilitate placement of ligating element 30 around the LAA,
and also can facilitate access by an appendage control device (see,
e.g., FIG. 6).
[0103] In some embodiments, device 10 can further include
positioning element 50, as depicted in FIG. 5. Device 10 also can
include outer sheath 60, where catheter 20 and positioning element
50 are contained within outer sheath 60. In some embodiments,
positioning element 50 can be contained within catheter 20.
Positioning element 50 can include loop 54 and elongate portion 56.
Loop 54 can encircle any portion of ligating element 30. For
example, loop 54 can encircle ligating element 30 at a position
proximate the base of lariat 43, as shown in FIG. 5A, or can
encircle ligating element 30 at or near the distal end of lariat
43. Elongate portion 56 can extend through the length of outer
sheath 60 or catheter 20, such that positioning element 50 can be
manipulated outside the body. In use, positioning element 50 can be
used to manipulate the position of ligating element 30 (e.g., to
deflect lariat 43, as shown in FIG. 5B), and thus can facilitate
placement of ligating element 30 around the base of the LAA. This
element may also potentially be used to loosen a knot after
placement and/or facilitate advancement of a cutter through the
sheath to remove a loop if, e.g., its position is deemed not
favorable.
[0104] Alternatively or in addition, ligating device 10 can include
appendage control means 70. Appendage control means 70 can be
contained within the lumen of catheter 20, as shown in FIG. 6, or
can be contained within an outer sheath. Appendage control means 70
can extend through the length of catheter 20 or through an outer
sheath, and can be in the form of, for example, a suction device, a
grasper device, cryogenic device, etc. In use, distal end 75 of
appendage control means 70 can be advanced out of catheter 20 and,
in some embodiments, through lariat 43, to contact the LAA and hold
or lift it into a position suitable for placement of ligating
element 30 over the LAA. Once ligating element 30 is placed around
the LAA, the LAA can be released from appendage control means 70 by
removal of suction if a suction device, by appropriate actuation if
a grasper device, or by warming if a cryogenic device. Appendage
control means 70 then can be retracted into device 10, or can be
advanced to re-grasp the LAA at, for example, a more proximal site,
permitting further advancement of control element 40 toward the
base of the LAA.
[0105] Once ligating element 30 is positioned around the base of
the LAA, control element 40 can be removed if desired. For example,
a clinician can pull on one end of control element 40 in the
direction of the arrow shown in FIG. 7 to remove it entirely or
partially from ligating element 30. In such an embodiment, the
control element 40 is preferably slidably fitted within the
ligating element 30, i.e., the control element 40 can be pulled out
of the ligating element 30 while the ligating element 30 remains in
its selected position (e.g., around an LAA, etc.). Alternatively,
control element 40 can be left within ligating element 30.
[0106] Ligating element 30 can be tightened and held in position
around the LAA using any suitable retention means including,
without limitation, a knot or a clip. For example, knot 80 can be
tied in ligating element 30 at a position outside the body, and can
be advanced along ligating element 30 through catheter 20 using any
suitable method or device, including those known in the art (such
as, e.g., a knot pusher (not shown)). FIG. 8 depicts knot 80 as it
approaches distal end 25 of catheter 20, while FIG. 9 depicts knot
80 as it can appear in position at a tightened loop around the LAA.
In some embodiments, a clip can be advanced through device 10
(e.g., through catheter 20 or through outer sheath 60) and
positioned around ligating element 30.
[0107] In some embodiments, ligating device 10 can include a means
for repositioning ligating element 30 after it has been tightened
around the LAA. As shown in FIG. 10, for example, positioning
element 50 can be used to reposition ligating element 30. By
pulling positioning element 50 in the direction of the arrow shown
in FIG. 10, a clinician can pull knot 90 toward catheter 20, such
that ligating element 30 can be loosened and/or repositioned.
[0108] In some embodiments, the control element threaded through
the lumen of a hollow ligating element may include portions of
different thickness. Referring to FIG. 10A, the catheter 20a has a
distal end 25a from which the lariat or loop 43a formed in the
ligating element 30a extends. A control element 40a extends through
a lumen in the ligating element 30a. One feature of the ligating
device depicted in FIG. 10A is that a knot 80a is formed in the
ligating element 30a while the control element 40a is located in
the portion of the ligating element 30a containing the knot
80a.
[0109] The control element 40a can include two or more different
portions. For example, the control element 40a can include a distal
portion located between the distal end 44a and the transition 45a,
and a proximal portion located between the transition 45a and the
proximal end (not shown) of the control element 40a. The proximal
end of the control element 40a (not shown) may preferably extend
outside of the proximal end (also not shown) of the catheter
20a.
[0110] An additional feature of the control element 40a depicted in
FIG. 10A is that the thickness of the distal portion of the control
element 40a (i.e., the portion between the distal end 44a and the
transition 45a) is less than the thickness of the proximal portion
of the control element 40a (i.e., the portion of the control
element 40a from the transition 45a to the proximal end of the
control element 40a). The thinner distal portion of the control
element 40a may be thin enough such that the knot 80a can be formed
in and advanced along the ligating element 30 such that the knot
80a is located proximate the distal end 25a of the catheter 20a
before the lariat 43a is advanced out of the catheter 20a. In
addition, the distal portion of the control element 40a may be thin
enough such that, after deployment of the ligating clement 30a, the
control element 40a can be removed from the ligating element 30a
by, e.g., pulling on the proximal end of the control element 40a
such that the distal portion of the control element 40a is removed
from the knot and the lariat or loop 43a.
[0111] Although the thickness differential in the control element
40a is depicted as occurring within a relatively small distance in
the embodiment of FIG. 10A, the thickness of the control element
40a may change gradually over a significant distance, provided that
the thickness of the control element 40a passing through the knot
80a does not prohibit removal of the control element 40a (if its
removal is desired).
[0112] Another exemplary embodiment of a ligating device 10b is
depicted in FIG. 10B. The depicted ligating device includes a
primary control element 40b and a secondary control element 48b,
both of which are threaded through portions of the ligating element
30b. As in previously described embodiments, the catheter 20b has a
distal end 25b from which the lariat or loop 43b formed in the
ligating clement 30b extends.
[0113] The ligating element 30b includes a first portion 32b
extending along the right side of the catheter 20b (as seen in FIG.
10B) towards the loop 43b. The ligating element 30b also includes a
second portion 33b extending along the left side of the catheter
20b (as seen in FIG. 10B) towards the loop 43b. A knot 80b is
formed in the ligating element 30b. More particularly, in the
depicted embodiment, the knot 80b is formed in the portion 32b of
the ligating element 30b, and the portion 33b of the ligating
element 30b extends through the knot 80b. As a result, the knot 80b
may be potentially referred to as a slip knot that can be advanced
along the portion 33b while the control element 40b remains in
position within the ligating element 30b.
[0114] The primary control element 40b preferably forms a loop 43b
as depicted, with the ligating element 30b conforming to the shape
of the loop 43b formed by the control element 40b. The primary
control element 40b has a distal end 44b that may preferably be
located distal of the knot 80b. In other words, the primary control
element 40b may preferably not extend into the knot 80b as formed
in portion 32b of the ligating element 30b. In another
characterization, the primary control element 40b may be described
as having a distal end 44b that is not located within or proximally
of the knot 80b (as delivered for use in a subject).
[0115] Although the portion of the primary control element 40b
within the left-hand portion 33b of the ligating element 30b does
extend through the knot 80b, that portion 33b of the ligating
element 80b is relatively straight and does not contain the bends
associated with the knot 80b. As a result, the control element 40b
may not need to be more rigid than, for example, the portion of the
control element 40a that extends through the knot 80a in ligating
device 10a as described in connection with FIG. 10A. That increased
rigidity may assist in forming loop 43b in the ligating element
30b
[0116] In some embodiments, it may be preferred that the distal end
44b of the primary control element 40b be located within the loop
43b (and not extend into the portion 32b of the ligating element
30b that leads to the loop 43b--see, for example, FIG. 7).
Alternatively, the primary control element 40b can be withdrawn
(retracted Proximally) as the knot 80b is advanced distally such
that the distal end 44b of the control element 40b remains outside
of the knot 80b as formed in portion 32b of the ligating element
30b.
[0117] The ligating device 10b depicted in FIG. 10B includes an
optional secondary control element 48b that extends through the
portion 32b of the ligating element 30b. It may be preferred that
the secondary control element 48b have a distal end 49b that is
located proximally of the knot 80b such that the secondary control
element 48b does not extend through the knot 80b. In some
embodiments, the secondary control element 48b may be advanced
distally as the knot 80b is advanced distally to provide support
and rigidity to the portion 32b of the ligating clement 30b as the
knot is advanced.
[0118] Once the clinician has determined that ligating element 30
is in a suitable position and does not need to be moved, a suitable
device (e.g., a scissors, scalpel, clipper, or any other useful
device) can be advanced through device 10 (e.g., along positioning
element 50) to cut ligating element 30 and control element 40, if
applicable, proximate the retention means (e.g., knot 90). Ligating
element 30 can be left in position around the base of the LAA, and
the remainder of device 10 can be removed from the subject's body.
Alternatively, if the position of ligating element 30 around the
LAA is deemed unsuitable, the cutting device can be used to cut
through lariat 43, permitting complete removal of ligating element
30.
[0119] Exemplary embodiments of the ligating devices in which the
ligating element is formed of rigid material and the control
element is formed of pliable material are depicted in FIGS. 11-15.
Ligating device 110 can include catheter 120 with a proximal end
(not shown) and distal end 125. Catheter 120 can contain ligating
element 130 connected to elongate element 135, which can extend
through the length of catheter 120. Catheter 120 also can contain
control element 140, which can be disposed within all or a portion
of ligating element 130.
[0120] In this embodiment, ligating element 130 can be formed of
shape memory material (e.g., Nitinol), and control element 140 can
be a suture or a pliable wire. Ligating element 130 can be
configured to have an original shape that is closed, (e.g., a
closed or flattened loop) as shown in FIGS. 11 and 12, for example.
A clinician can advance ligating element 130 out of distal end 125,
and then can open ligating element 130 by actuating control element
140.
[0121] For example, with embodiments in which control element 140
extends through catheter 120, into and completely through ligating
element 130, and back through catheter 120, (as depicted in FIGS.
12 and 13A), both ends of control element 140 can protrude from the
proximal end of catheter 120. By pulling on both ends of control
element 140 in the direction of the arrows shown in FIG. 13A, a
clinician can actuate ligating element 130, causing it to open.
[0122] In other embodiments, control element 140 can extend through
catheter 120 and into ligating element 130, where it can be secured
at or near distal end 145 of ligating element 130 (e.g., at point
148). In such embodiments, as depicted in FIG. 13B, one end of
control element can protrude from the proximal and of catheter 120.
A clinician can pull on the protruding end of control element 140
to open ligating element 130. In either case, actuation of control
element 140 can cause ligating element 130 to expand and form
lariat 143, which can be suitable for positioning around the
LAA.
[0123] Ligating device 110 can further include positioning element
150 and pivot pin 155, shown in FIGS. 14 and 15. Pivot pin 155 can
be located at the junction of ligating element 130 and elongate
element 135, and in some embodiments can be used to connect
ligating element 130 to elongate element 135. Positioning element
150 can be contained within catheter 120, as shown in FIGS. 14 and
15, or can be contained within an outer sheath. Positioning element
150 can include loop 160 and elongate portion 165. Loop 160 can
encircle a portion of ligating element 130. A clinician can pull on
elongate portion 165 of positioning element 150 in the direction
indicated by the arrow in FIG. 13. The resulting force of loop 160
on ligating element 130 can cause ligating element 130 to rotate
about pivot pin 155, so that ligating element 130 is at an angle
with respect to elongate element 135: Ligating element 130 can be
adjusted to any suitable angle with respect to elongate element 135
(e.g., an angle of about 20, 30, 40, 45, 50, 60, 70, 80, 85, 90,
95, 100, 110, 120, 130, 135, 140, 145, or 150 degrees). Typically,
positioning element 150 can be used to adjust the angle of ligating
element 130 after lariat 143 is formed by pulling on control
element 140. In some embodiments, however, the angle of ligating
element 130 can be adjusted before or after lariat 143 is
formed.
[0124] Once ligating element 130 is in place around the LAA,
control element 140 can be released, allowing ligating element 130
to assume its original shape and thus tighten or close around the
base of the LAA. Control element 140 can be removed from ligating
element 130, or can be left within the interior of ligating element
130. After a clinician is satisfied with the position of ligating
element 130 around the LAA, a suitable cutting or detaching device
(e.g., a scissors, scalpel, clipper, or any other useful device)
can be advanced through device 110 to detach ligating element 130
(and control element 140, if applicable) from elongate portion 135.
Ligating element 130 can be left in position around the base of the
LAA, and the remainder of device 110 can be retracted from the
subject's body.
[0125] In the exemplary embodiments depicted in FIGS. 16-18,
ligating device 210 can have catheter 220 with a proximal end (not
shown) and distal end 225, with ligating element 230, elongate
element 235, and hollow donut-shaped control element 240 contained
therein. Elongate element 235 can extend through the length of
catheter 220, and control element 240 can be connected to elongate
element 235 and positioned at or near distal end 225. Ligating
element 230 can be contained within control element 240, as shown
in FIGS. 16-18, or can encircle the outer circumference of control
element 240.
[0126] In some embodiments, ligating element 230 can be a ring clip
whose natural position is closed (i.e., in the absence of external
forces, the ligating element 230 is in the closed position as
depicted in FIG. 16). Ligating element 230 can be formed of, e.g.,
Nitinol or any other suitable shape memory material. Control
element 240 can be formed of soft pliable material (e.g., PTFE,
polyethylene, or polypropylene) that is air tight. Control element
240 also can provide an atraumatic covering for ligating element
230 if ligating element 230 is contained within control element
240, or can serve as a tissue protector if ligating element 230
extends around the circumference of control element 240.
[0127] In some embodiments, ligating device 210 includes a conduit
in fluid communication with control element 240. For example,
elongate element 235 can be conduit 250 in fluid communication with
the interior of control element 240. Alternatively, ligating device
210 can include a separate fluid conduit. Conduit 250 can have a
length such that it can extend through catheter 220 (or through an
outer sheath containing catheter 220, if applicable) between the
proximal end and distal end 225. A clinician can pass fluid into
conduit 250 from outside the subject's body. In these embodiments,
ligating device 210 can be deployed by inflating control element
240 with, for example, a gas (e.g., air, oxygen, or nitrogen) or a
liquid (e.g., saline or water) passed through conduit 250.
Inflation of control element 240 can cause ligating element 230 to
open, forming lariat 243.
[0128] In some embodiments, ligating device 210 can further include
positioning element 260, shown in FIG. 18. Positioning element 260
can have a length such that it can extend through catheter 220
between the proximal end and distal end 225. In some embodiments,
positioning element 260 can be reversibly attached to control
element 240.
[0129] A clinician can then position ligating device 210 at the
base of the LAA and deflate control element 240 to close ligating
element 230. For example, a clinician can remove conduit 250 from
control element 240. The removal of conduit 250, in combination
with inward pressure exerted by ligating element 230, can cause
control element 240 to deflate. Once device 210 is positioned
around the base of the LAA and deflated, a clinician can detach
fluid conduit 250 and positioning element 260, if applicable, from
ligating element 230 and control element 240. The remainder of
ligating device 210 can be removed from the subject's body, while
ligating element 230 and control element 240 remain.
[0130] In the exemplary embodiments depicted in FIGS. 19 and 20,
ligating device 310 can include catheter 320 with a proximal end
(not shown) and distal end 325. Ligating element 330 and control
element 340 can be positioned within catheter 320. Control element
340 can include first elongate portion 341 and second elongate
portion 342. Ligating element 330 can be attached to the distal
ends of elongate portions 341 and 342. A clinician can manipulate
first and second elongate portions 341 and 342 with respect to one
another, and can cause ligating element 330 to form lariat 343, as
shown in FIG. 20. Lariat 343 can be positioned around the base of
the LAA, and a clip or other suitable fastening means can he passed
through catheter 320 to retain ligating element 330 in position. A
cutting device can he used to sever lariat 343 from the remainder
of ligating element 330, and the device can be removed from the
subject's body.
[0131] In the exemplary embodiments shown in FIGS. 21 and 22,
ligating device 410 includes a catheter 420 with a proximal end
(not shown) and distal end 425, wherein control element 440 is
positioned within the lumen of catheter 420. Control element 440
can be formed using a substantially rigid material (e.g., wire).
Control element 440 can have a generally elongate "U" shape, such
that it can extend through the length of catheter 420, with both
ends protruding from the proximal end of catheter 420 and the
bottom of the "U" positioned at or near distal end 425 of catheter
420. A lariat or loop can form when the distal end of control
element 440 is advanced out of distal end 425, as shown in FIG.
21.
[0132] Ligating element 430 can be attached to one end of control
element 440, and can be, for example, a suture. Device 410 also can
include a guard 450, which can be a hollow, flexible suture or
sheath that covers the portion of control element 440 that is to be
placed around the LAA (or other anatomical structure). Although the
guard 450 is depicted as terminating relatively close to the loop,
the guard 450 could alternatively extend towards the proximal end
of the catheter 420 (even as far as extending out of the proximal
end of the catheter 420).
[0133] Device 410 also can include a positioning element (not
shown) to facilitate placement of control element 440 (around,
e.g., the base of the LAA). When control element 440 is suitably
positioned around the LAA, a clinician can pull on the free end of
control element 440 in the direction indicated by the arrow in FIG.
22, advancing ligating element 430 toward distal end 425 of
catheter 420 and through guard 450, as shown in FIG. 22, such that
ligating element 430 takes the place of the control element 440 and
is positioned around the LAA. Any suitable mechanism (e.g., a clip
or a knot and described herein) then can be used to retain ligating
element 430 in position. Excess portions of ligating element 430
(e.g., portions that are not positioned around the LAA) can be cut,
and the device can be removed from the subject's body.
[0134] The devices depicted in FIGS. 23 through 26 are examples of
devices that can be used for placement of a ligating device via the
CS. Device 510 can include sheath 520, hollow needle 530, and wire
540, which can each have a proximal end (not shown) and distal ends
525, 535, 545, respectively. In some embodiments, device 510 does
not include needle 530. As shown in FIGS. 23 and 24, distal end 525
of sheath 520 can be tapered. In some embodiments, distal end 525
is not tapered.
[0135] Device 510 can be advanced into CS 550, and needle 530
and/or wire 540 can pierce the wall of CS 550. Any suitable methods
can be used to pierce the wall of CS 550 and to prevent wire 540 or
needle 530 from puncturing the pericardial sac. As depicted in FIG.
24, for example, distal end 545 of wire 540 can be configured to
coil after being deployed out of device 510 and through the wall of
CS 550. As shown in FIG. 25, distal end 535 of needle 530 can be
curved, such that when distal end 545 of wire 540 exits needle 530,
it is directed toward the wall of CS 550.
[0136] In some embodiments, means can be used to reduce or prevent
the flow of blood from out of the CS and into the pericardial
space. As shown in FIG. 26, for example, balloon 560 can be passed
through device 510, and can be inflated within the lumen of the CS.
Balloon 560 can be connected to fluid conduit 565, through which a
fluid such as air, oxygen, saline, or water, for example, can be
passed to inflate and deflate balloon 560. Balloon 560 can be
passed through sheath 520 in an uninflated state, and can be
inflated once it is within the lumen of the CS. When inflated,
balloon 560 can reduce the flow of blood, indicated by the arrow in
FIG. 26, into the pericardial space through the opening created by
wire 540.
[0137] In some embodiments, device 510 also can include means for
closing an opening in the CS wall after completion of a procedure
(e.g., ligation of the LAA, atrial ablation, or pericardial
mapping) within the pericardial space. In some cases, a wire having
a RF tip at its distal end can be passed through the sheath or the
needle of a device. Once the tip of the wire reaches the opening in
the CS wall, RF energy can be used to weld the opening. For
example, as depicted in FIG. 27, device 510 can contain wire 570
having RF tip 575. As shown, wire 570 can be advanced through
needle 530 until RF tip 575 reaches opening 555 in the wall of CS
550, and RF energy can be applied to weld tissue adjacent to
opening 555.
[0138] In some cases, a suction device having needles or RF tipped
wires disposed therein can be used to close an opening in the CS
wall. As shown in FIG. 28, for example, device 510 can have hollow
suction catheter 580 extending therethrough. Suction catheter 580
can have a proximal end (not shown), distal end 582 and side
opening 585, and can contain (e.g., within its lumen or within
longitudinal channels within its walls) needles 590 and 592, which
can have distal ends 595 and 597, respectively. Suction catheter
580 can be advanced through sheath 520 until side opening 585 is
positioned adjacent to opening 555 in the wall of CS 550. Suction
can be used to pull tissue around opening 555 into side opening 585
of catheter 580, and needles 590 and 592 can be manipulated to
physically suture tissue adjacent to opening 555. Once opening 555
is suitably closed, device 510 can he withdrawn from the subject's
body.
[0139] It is to be understood that while the invention has been
described in conjunction with the detailed description thereof, the
foregoing description is intended to illustrate and not limit the
scope of the invention, which is defined by the scope of the
appended claims. Other aspects, advantages, and modifications are
within the scope of the following claims.
* * * * *